Abstract: In order to meet the multi-scale simulation requirements in the flood control operation process,the present dynamic visualization techniques in flood control operation was concluded,and a set of multi-scale simulation methods based on 3D GIS technique were studied,which can conduct multi-scale simulation on time-varying rainfall and flood composition,reservoir flood storage and discharge,reservoir area inundation,evolution of middle and lower rivers,flood discharge in flood storage and detention areas etc.Based on this,a program framework for 3D dynamic operation of reservoir groups was formed to quickly build the flood control process.Taking the typical floods in 1954 as an example,the flood control operation process based on existing flood control engineering facilities was simulated in the 3D GIS framework.The experimental results showed that the multi-scale simulation methods based on 3D GIS can not only clearly describe the general overview,but also simulate the local flood situation and effectiveness,and reflect the whole process of joint operation of reservoir groups more intuitively and dynamically.